I would like to use aggregate() to combine statistics
for several days in a data frame. My data frame looks
similar to this:
datetype count value
1 2006-04-01 A 10 99.6
2 2006-04-01 B 4 33.2
3 2006-04-02 A 22 43.2
4 2006-04-02 B 8 44.9
5
Does this do what you want?
x
date type count value
1 2006-04-01A10 99.6
2 2006-04-01B 4 33.2
3 2006-04-02A22 43.2
4 2006-04-02B 8 44.9
5 2006-04-03A12 12.4
6 2006-04-03B14 18.5
y - lapply(split(1:nrow(x), x$type), function(.ind){
+
Here are three possibilities:
1. aggregate on the columns that you want to sum and aggregate on
the columns that you want to average and then merge them:
By - A[, 2, drop = FALSE]
merge(aggregate(A[, 3, drop = FALSE], By, sum),
aggregate(A[, 4, drop = FALSE], By, mean))
2. use by:
f -
